Extendible conveyor

ABSTRACT

An extendible conveyor apparatus includes a first end, a second end, and an adjustable-length bed of rollers extending in between them. A sliding frame (or extension) mounted moveably on a support structure supports a fixed number of the rollers, while a moveable string of rollers connected to a second end of the frame feeds additional rollers into and out of position between the second end of the conveyor apparatus and the frame according to frame movement between retracted and extended positions of the frame. In one embodiment, the bed of rollers includes at least some motor-driven rollers (MDRs) and the string of rollers withdraws to a position below the bed using an extend/retract drive mechanism having a drive chain disposed in a loop, the frame being connected to an upper side of the loop for frame-moving purposes and the string of rollers being connected to a lower side of the loop for string withdrawal purposes.

BACKGROUND OF THE INVENTION

1. Technical Field

This invention relates generally to conveyors and conveyor systems, andmore particularly to an extendible conveyor apparatus with rollersarranged in an adjustable-length bed suitable for any of variousconveyor applications.

2. Description of Related Art

Some conveyor applications require a conveyor that the user can adjustin overall length. The user can lengthen or shorten the conveyor to suitoperating needs. A typical existing gravity conveyor, for example, mightinclude multiple fixed-length, skate wheel conveyor sections inoverlapping relationship. The amount of overlap is adjusted to achievethe desired overall length. An existing form of belt conveyor, mightinclude multiple fixed-length belt conveyor sections and belt-to-belttransfer plates. Yet another existing form of conveyor might includespaced-apart rollers mounted between extendible side rails havingcrisscrossed members that enable a user to extend them something like ascissors boom.

Although effective in many respects, existing conveyors often havecertain problems that make them unsuited for many extendible conveyorapplications. Gravity conveyors rely on gravity to move the parcels orother objects being conveyed. They don't work when level or inclinedupwardly. In addition, overlapping gravity conveyor sections result inabrupt vertical steps between overlapping sections that may beunacceptable. Multiple-belt conveyors involve weight, noise, andcomplicated construction, and extendible conveyors withscissor-boom-like side rails cause roller spacing to change when movedbetween retracted and extended positions. For these and other reasonsthat will become more apparent from the following description, usersneed a better extendible conveyor.

SUMMARY OF THE INVENTION

This invention addresses the concerns outlined above by providing anextendible conveyor apparatus having an adjustable-length bed ofrollers. An extendible frame (also referred to as a “slide frame” and asan “extension”) supports a fixed number of the rollers, while a moveablestring of rollers feeds additional rollers into and out of positionbehind the extendible frame according to movement of the frame. Thisarrangement of an extendible frame with a flexible string of rollersattached results in an adjustable-length bed of rollers. In that way,the invention provides an extendible conveyor apparatus having anadjustable-length bed that avoids many concerns of existingadjustable-length conveyors.

To paraphrase some of the more precise language appearing in the claimsand further introduce the nomenclature used, the invention provides aconveyor apparatus having a first end (e.g., a receiving end), a secondend (e.g., a discharge end), and an adjustable length between the firstand second ends. A bed of rollers extends from the first end of theconveyor apparatus to the second end, and a moveable frame supports afixed number of the rollers. The frame extends from a first end of theframe that is the first end of the conveyor apparatus to a second end ofthe frame that is disposed toward the second end of the conveyorapparatus. The frame is supported moveably for movement relative to thesecond end of the conveyor apparatus, between retracted and extendedpositions of the frame.

According to a major aspect of the invention, means are provided forfeeding additional rollers into and out of position between the secondend of the conveyor apparatus and the second end of the frame accordingto movement of the frame. The means for doing so includes a moveablestring of rollers connected to the second end of the frame. As anoperator moves the frame toward the extended position (therebylengthening the conveyor apparatus), the string of rollers follows theframe to feed additional rollers into position between the second end ofthe conveyor apparatus and the second end of the frame. As the operatormoves the frame toward the retracted position (thereby shortening theconveyor apparatus), the string of rollers is withdrawn so that anappropriate number of rollers are withdrawn from the bed of rollersaccording to frame position.

In a preferred embodiment of the invention, the string of rollersincludes at least some motor-driven rollers (MDRs), with the rollersbeing supported by a pair of flexible side rails disposed inspaced-apart parallel relationship to each other. The rotational axes ofthe rollers extend between the flexible side rails in spaced-apartparallel relationship to each other. Preferably, the flexible side railsinclude first and second chain members. In addition, the string ofrollers is arranged so that with the frame in the retracted position,the string of rollers extends downwardly from the discharge end of theconveyor apparatus to a storage position of the chain of rollers belowthe second end of the conveyor apparatus (beneath the moveable frame).The string of rollers is arranged (i) so that as the frame is moved fromthe retracted position to the extended position, the string of rollersis pulled by the frame into a position between the second end of theconveyor apparatus and the second end of the frame, and (ii) so that asthe frame is moved from the extended position to the retracted position,the string of rollers is withdrawn to a storage position of the stringof rollers below the second end of the conveyor apparatus.

The means for supporting the frame moveably includes a support structureon which the frame is mounted moveably, and means on the supportstructure for moving the frame under operator control between theretracted and extended positions. The means for moving the frame isarranged to withdraw the string of rollers as the frame is moved towardthe retracted position. Preferably, the means for doing so includes adrive mechanism beneath the frame having a drive chain disposed in aloop, with the frame being connected to an upper first side of the loopfor frame-moving purposes and the string of rollers being connected to alower second side of the loop for string withdrawal purposes. The actionof an operator moving the drive chain with a hand crank mechanism movesthe frame, with the string of rollers following frame movement.

Thus, the invention avoids many concerns of existing adjustable-lengthconveyors by providing an extendible conveyor apparatus having anadjustable-length bed of rollers. An extendible frame supports a fixednumber of the rollers, while a moveable string of additional rollersfeeds the additional rollers into and out of position in the bedaccording to movement of the frame. The following illustrative drawingsand detailed description make the foregoing and other objects, features,and advantages of the invention more apparent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 of the drawings is a three-dimensional view of the top, first orreceiving end, and right side of an extendible conveyor apparatusconstructed according to the invention, with the extendible frame shownin a partially extended position;

FIG. 2 a is a top plan view of the extendible conveyor apparatus withthe extendible frame in a fully retracted position;

FIG. 2 b is a top plan view of the extendible conveyor apparatus withthe extendible frame in a fully extended position;

FIG. 3 a is an enlarged side elevation view of the conveyor apparatuswith the extendible frame in the fully retracted position;

FIG. 3 b is a side elevation view similar to FIG. 3 a but with theextendible frame in the fully extended position and the conveyorapparatus foreshortened for illustrative purposes;

FIG. 4 shows details of the conveyor apparatus components identifiedwith a circle 4 in FIG. 3 a;

FIG. 5 shows details of the conveyor apparatus components identifiedwith a circle 5 in FIG. 3 a;

FIG. 6 is an enlarged elevation view of the first or receiving end ofthe conveyor apparatus;

FIG. 7 is an enlarged elevation view as viewed in a transverse planedisposed intermediate the first or receiving end and the second ordischarge end of the conveyor apparatus;

FIG. 8 is an enlarged elevation view of as viewed in a transverse planeextending through the crank mechanism;

FIG. 9 a is a diagrammatic view of the essential elements of theconveyor apparatus with the extendible frame in the fully retractedposition;

FIG. 9 b is a diagrammatic view of the conveyor apparatus with theextendible frame in a partially extended position; and

FIG. 9 c is a diagrammatic view of the conveyor apparatus with theextendible frame in the fully extended position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The drawings show various aspects of an extendible conveyor apparatus 10constructed according to the invention. Generally, the conveyorapparatus 10 includes a first end 11 (e.g., a receiving end), a secondend 12 (e.g., a discharge end), and a bed 13 of rollers extendingbetween the first and second ends 11 and 12 of the conveyor apparatus 10(FIG. 1). For the illustrated conveyor apparatus 10, the bed 13 ofrollers includes at least some motor-driven rollers 14A (the MDRs 14Aare shaded for ease of identification) and some unpowered rollers 14B.Just a single motor-driven roller 14A and a single unpowered roller 14Bare identified in FIG. 1 for illustrative purposes.

A moveable frame 15 supports a fixed number of the rollers 14A and 14Bon a support structure 16. The frame 15 extends from a first end 15A ofthe frame 15 that is the first end 11 of the conveyor apparatus 10, to asecond end 15B of the frame 15 that is disposed toward the second end 12of the conveyor apparatus 10. The frame 15 is mounted moveably on thesupport structure 16 for movement relative to the second end 12 of theconveyor apparatus 10 as depicted by a double-headed arrow 17 in FIG. 1.The support structure 16 helps serve the function of supporting theframe 15 moveably for movement relative to the second end 15B of theconveyor apparatus 10, between retracted and extended positions of theframe 15. An operator (not shown) turns a crank handle 18 to move theframe 15 and thereby adjust the length of the bed 13 of rollers (i.e.,adjust the length of the conveyor apparatus 10).

According to a major aspect of the invention, the conveyor apparatus 10includes means for feeding additional rollers 14A and 14B into and outof position between the second end 12 of the conveyor apparatus 10 andthe second end 15B of the frame 15 according to movement of the frame15. The means for doing so includes a moveable string 19 of rollersconnected to the second end 15B of the frame 15. As the frame 15 movesin a first direction to increase the length of the bed 13 of rollers,the string 19 of rollers follows the frame 15 and thereby feedsadditional rollers 14A and 14B into position between the second end 12of the conveyor apparatus 10 and the second end 15B of the frame 15. Asthe frame 15 moves in an opposite direction to decrease the length ofthe bed 13, the string 19 of rollers is withdrawn so that rollers 14Aand 14B are withdrawn from their position in the bed 13 of rollers.

FIGS. 2 a and 2 b are top plan views of the conveyor apparatus 10 thatillustrate the frame 15 in the fully retracted and fully extendedpositions of the frame 15. The length of the frame 15 is depicted by adouble-headed arrow dimension line 20 in FIGS. 2 a and 2 b. The frame 15is shown in a fully retracted position of the frame 15 in FIG. 2 a andin a fully extended position of the frame 15 (FIG. 2 b).

As an idea of size, the illustrated conveyor apparatus 10 is roughlyabout 11 feet long between the first and second ends 11 and 12 of theconveyor apparatus 10, while the moveable frame 15 is roughly about 10feet long between the first and second ends 15A and 15B of the frame 15.Of course, those dimensions may vary significantly according to theparticular conveyor design without departing from the inventive conceptsdisclosed.

As for the motor-driven rollers 14A, they may take the form ofcommercially available powered conveyor rollers having 24-volt internaldirect current (DC) motors, such as, for example, the 20-inch longpowered conveyor rollers available from Sparks Belting Company of GrandRapids, Mich. The unpowered rollers 14B are similar in exterior size andshape to the MDRs 14A, but they do not include an internal motor. TheMDRs 14A are spaced apart sufficiently to accommodate eleven unpoweredrollers 14B in between two MDRs 14A. Every twelfth roller is an MDR 14A.The unpowered rollers 14B are driven by the MDRs 14A, being coupledmechanically to the MDRs 14A by O-ring couplings or other suitablecoupling means. Suitable electrical wiring and control circuitry (notshown) couples electrical power to the MDRs 14A. The MDRs 14A are shadedin FIGS. 1, 2 a, and 2 b for illustrative purposes to highlight thisarrangement.

Notice with reference to FIGS. 3 a and 3 b that for the illustratedconveyor apparatus 10, the bed 13 of rollers is flat. In other words,the rotational axes of those rollers 14A and 14B that occupy positionsin the bed 13 of rollers, all lie in a common plane 21 without abruptvertical steps, and thus the bed 13 of rollers is flat. The rollersurface of the bed 13 of rollers is continuous and in a common planewithout vertical steps, even as the length of the bed 13 of rollers ischanged. From the foregoing and subsequent descriptions, one of ordinaryskill in the art can readily implement the invention so that therotational axes of those rollers 14A and 14B that occupy positions inthe bed 13 of rollers do not lie in a common plane, thereby resulting ina bed of rollers that extends in a gradual curve instead (i.e., theresulting bed of rollers is not flat). Such variations are intended tofall within the inventive concepts disclosed and the broader claimssubsequently presented.

FIGS. 3 a and 3 b also illustrated further details of the string 19 ofrollers and a drive mechanism 22. According to one aspect of theinvention, the conveyor apparatus 10 includes means on the supportstructure 16 for moving the frame 15 under operator control between theretracted and extended positions of the frame 15 and for withdrawing thestring 19 of rollers as the frame 15 is moved toward the retractedposition. The drive mechanism 22 helps serve this function. It includesa chain 23 disposed in a loop over sprockets 24 and 25. The frame 15 isconnected to an upper first side 23A of the loop and the string 19 ofrollers is connected to a lower second side 22B of the loop.

As the operator turns the crank 18 mentioned previously with referenceto FIG. 1, a crank mechanism 18A (of which the crank 18 is a part)causes the chain 23 to move over the sprockets 24 and 25 and that causesthe frame 15 to move between the retracted and extended positions of theframe 15. Turning the crank 18 in a first direction (e.g., clockwise)moves the frame 15 toward the extended position. Turning the crank in anopposite second direction (e.g., counterclockwise) moves the frame 15toward the retracted position while also withdrawing the string 19 ofrollers.

Stated another way, the support structure 16 supports the frame 15moveably, and means are provided on the support structure 16 for movingthe frame 15 under operator control between the retracted and extendedpositions. The means for doing so also withdraws the string 19 ofrollers as the frame 15 is moved toward the retracted position. Thedrive mechanism 22 does this, including the chain 23 disposed in a loop,with the frame 15 being connected to a first side 23A of the loop forframe-moving purposes and the string 19 of rollers being connected to asecond side 23B of the loop for string withdrawal purposes. The string19 of rollers is arranged so that with the frame 15 in the retractedposition, the string 19 of rollers extends downwardly from the secondend 12 of the conveyor apparatus 10 to a storage position of the string19 of rollers below the second end 12. As the frame is 15 moved from theretracted position to the extended position, the string 19 of rollers ispulled by the frame 15 into a position between the second end 12 of theconveyor apparatus 10 and the second end 15B of the frame 15. As theframe 15 is moved from the extended position to the retracted position,the string 19 of rollers is withdrawn to a storage position of thestring 19 of rollers below the second end 12 of the conveyor apparatus10.

FIGS. 4 and 5 are enlarged views showing further details of theconnections to the chain 23. The string 19 of rollers loops oversprockets 26 and 27 (FIG. 4) in extending from second end 12 to aposition beneath the bed 13 of rollers where it is connected to thesecond side 23B of the loop in which the chain 23 of the drive mechanism22 is disposed. A suitable connector assembly 28 (FIG. 4) serves toconnect the string 19 of rollers to the second side 23B of the loop,while a suitable connector arrangement 29 (FIG. 5) serves to connect theframe 15 to the first side 23A.

The string 19 of rollers is a flexible assembly of a series of multiplerollers connected in a line so that the string 19 of rollers can changedirection and move over the sprockets as illustrated and described. Theillustrated string 19 of rollers includes a pair of flexible side railsdisposed in spaced-apart parallel relationship to each other, and aplurality of rollers extending between the flexible side rails. For theillustrated conveyor apparatus 10, the side rails include first andsecond chain members disposed in spaced-apart parallel relationship toeach other, just one chain member 30 being identified in FIGS. 4 and 5.The chain member 30 may, for example, take the form of a known andcommercially available American National Standards Institute (ANSI)standard steel roller chain (e.g., double pitch K-1 attachment chainavailable from McMaster-Carr Supply Company).

FIG. 6 is an enlarged elevation view of the first end 11 of the conveyorapparatus 10. The frame 15 includes optional side guards 31A and 31B.Removable side guards 32A and 32B help partition the bed 13 of rollersfrom the surrounding environment. The frame 15 slides on rollers 33A and33B FIG. 7 is a further enlarged elevation view as viewed in atransverse plane extending through the string 19 of rollers intermediatethe second end 12 of the conveyor apparatus 10 and the second end 15B ofthe frame 15. An MDR 35 is shown mounted on a full-width roller supportbracket 36. Full-width roller support brackets occur every 15 inches ofpitch. An unpowered roller 37 is shown mounted between mounting brackets38A and 38B. FIG. 8 is an enlarged elevation view as viewed in atransverse plane extending through the crank mechanism.

Thus, the invention provides an extendible conveyor apparatus 10 havingan adjustable-length bed 13 of rollers. An extendible frame 15 supportsa fixed number of the rollers, while a moveable string 19 of rollersfeeds additional rollers into and out of position in the bed 13according to movement of the frame 15. From the foregoing and subsequentdescriptions, one of ordinary skill in the art can readily implement theinvention. FIGS. 9 a, 9 b, and 9 c diagrammatically review essentialelements of the conveyor apparatus 10 using the reference numeralsmentioned above, with FIG. 9 a showing the frame 15 in the fullyretracted position, FIG. 9 b showing the frame 15 in an intermediateposition, and FIG. 9 c showing the frame 15 in a fully extendedposition. Although an exemplary embodiment has been shown and described,one of ordinary skill in the art may make many changes, modifications,and substitutions without necessarily departing from the spirit andscope of the invention.

1. A conveyor apparatus having a first end, a second end, and anadjustable length between the first end and the second end, the conveyorapparatus comprising: a bed of rollers extending from the first end ofthe conveyor apparatus to the second end of the conveyor apparatus; aframe supporting a fixed number of the rollers, the frame extending froma first end of the frame that is the first end of the conveyorapparatus, to a second end of the frame that is disposed toward thesecond end of the conveyor apparatus; means for supporting the framemoveably for movement relative to the second end of the conveyorapparatus, between retracted and extended positions of the frame; andmeans for feeding additional rollers into and out of position betweenthe second end of the conveyor apparatus and the second end of the frameaccording to movement of the frame, including a string of rollersconnected to the second end of the frame.
 2. A conveyor apparatus asrecited in claim 1, wherein the string of rollers includes a pair offlexible side rails disposed in spaced-apart parallel relationship toeach other, and a plurality of rollers extending between the flexibleside rails.
 3. A conveyor apparatus as recited in claim 2, wherein theflexible side rails include first and second chain members disposed inspaced-apart parallel relationship to each other.
 4. A conveyorapparatus as recited in claim 1, wherein the string of rollers isarranged so that with the frame in the retracted position, the string ofrollers extends downwardly from the second end of the conveyor apparatusto a storage position of the string of rollers below the second end ofthe conveyor apparatus.
 5. A conveyor apparatus as recited in claim 1,wherein the string of rollers is arranged (i) so that as the frame ismoved from the retracted position to the extended position, the stringof rollers is pulled by the frame into a position between the second endof the conveyor apparatus and the second end of the frame, and (ii) sothat as the frame is moved from the extended position to the retractedposition, the string of rollers is withdrawn to a storage position ofthe string of rollers below the second end of the conveyor apparatus. 6.A conveyor apparatus as recited in claim 1, wherein the means forsupporting the frame moveably includes: a support structure on which theframe is mounted moveably; and means on the support structure for movingthe frame under operator control between the retracted and extendedpositions while withdrawing the string of rollers as the frame is movedtoward the retracted position.
 7. A conveyor apparatus as recited inclaim 6, wherein said means on the support structure for moving theframe under operator control includes a drive mechanism having a chaindisposed in a loop, with the frame being connected to a first side ofthe loop for frame-moving purposes and the string of rollers beingconnected to a second side of the loop for string withdrawal purposes.8. A conveyor apparatus as recited in claim 1, wherein the bed ofrollers includes at least some motor-driven rollers.
 9. A conveyorapparatus as recited in claim 8, wherein the bed of includes at leastsome non-motor-driven rollers that do not include a drive motor, saidnon-motor-driven rollers being mechanically coupled to the motor-drivenrollers.
 10. A conveyor apparatus having a first end, a second end, andan adjustable length between the first end and the second end, theconveyor apparatus comprising: a bed of rollers extending from the firstend of the conveyor apparatus to the second end of the conveyorapparatus; a frame supporting a fixed number of the rollers, the frameextending from a first end of the frame that is the first end of theconveyor apparatus to a second end of the frame disposed toward thesecond end of the conveyor apparatus; means for supporting the framemoveably for movement relative to the second end of the conveyorapparatus between retracted and extended positions of the frame,including a support structure and means on the support structure formoving the frame under operator control between the retracted andextended positions; and means for feeding additional rollers into andout of position between the second end of the conveyor apparatus and thesecond end of the frame according to movement of the frame, including astring of rollers connected to the second end of the frame; said meanson the support structure for moving the frame under operator controlalso withdrawing the string of rollers as the frame is moved toward theretracted position.